Novel biomaterials that release a controlled dose of an anti-thrombotic peptide into the blood will be prepared. These biomaterials should be more biocompatible because they inhibit coagulation in the region it is likely to occur, namely at the blood polymer interface. A low temperature glow discharge plasma deposition technology will be used to form very thin, crosslinked coatings that limit the rate of release of a peptide incorporated into the underlying material. Variations in the coating conditions will allow us to prepare materials that release various peptides at the desired rate. Besides anti-thrombotics, other peptides of biomedical usefulness could be delivered in this way because this is a somewhat general method that is not specific to the particular peptide/polymer pair.